<template>
  <!-- 城市选择-->
  <view class="city-select">
    <scroll-view
      :scroll-top="scrollTop"
      scroll-y="true"
      class="city-select-main"
      id="city-select-main"
      :scroll-into-view="toView"
    >
      <!-- 预留搜索-->
      <view class="city-serach" v-if="isSearch"
        ><input
          @input="keyInput"
          :placeholder="placeholder"
          class="city-serach-input"
      /></view>
      <!-- 当前定位城市 -->
      <view class="hot-title" v-if="activeCity && !serachCity"
        >当前定位城市</view
      >
      <view class="hot-city" v-if="activeCity && !serachCity">
        <view class="hot-item" @click="cityTrigger(activeCity)">{{
          activeCity[formatName]
        }}</view>
      </view>
      <!-- 热门城市 -->
      <view class="hot-title" v-if="hotCity.length > 0 && !serachCity"
        >热门城市</view
      >
      <view class="hot-city" v-if="hotCity.length > 0 && !serachCity">
        <template v-for="(item, index) in hotCity" :key="index + 1">
          <view @click="cityTrigger(item, 'hot')" class="hot-item">{{
            item[formatName]
          }}</view>
        </template>
      </view>
      <!-- 城市列表(搜索前) -->
      <view class="citys" v-if="!serachCity">
        <view
          v-for="(city, index) in sortItems"
          :key="index"
          v-show="city.isCity"
          class="citys-row"
        >
          <view
            class="citys-item-letter"
            :id="'city-letter-' + (city.name === '#' ? '0' : city.name)"
            >{{ city.name }}</view
          >
          <view
            class="citys-item"
            v-for="(item, inx) in city.citys"
            :key="inx"
            @click="cityTrigger(item)"
            >{{ item.cityName }}</view
          >
        </view>
      </view>
      <!-- 城市列表(搜索后)  -->
      <view class="citys" v-if="serachCity">
        <view
          v-for="(item, index) in searchDatas"
          :key="index"
          class="citys-row"
        >
          <view class="citys-item" :key="inx" @click="cityTrigger(item)">{{
            item.name
          }}</view>
        </view>
      </view>
    </scroll-view>
    <!-- 城市选择索引-->
    <view class="city-indexs-view" v-if="!serachCity">
      <view class="city-indexs">
        <view
          v-for="(cityIns, index) in handleCity"
          class="city-indexs-text"
          v-show="cityIns.isCity"
          :key="index"
          @click="cityindex(cityIns.forName)"
        >
          {{ cityIns.name }}
        </view>
      </view>
    </view>
  </view>
</template>

<script>
import citySelect from './citySelect.js';
export default {
  props: {
    //查询提示文字
    placeholder: {
      type: String,
      default: '请输入城市名称',
    },
    //传入要排序的名称
    formatName: {
      type: String,
      default: 'cityName',
    },
    //当前定位城市
    activeCity: {
      type: Object,
      default: () => null,
    },
    //热门城市
    hotCity: {
      type: Array,
      default: () => [],
    },
    //城市数据
    obtainCitys: {
      type: Array,
      default: () => [],
    },
    //是否有搜索
    isSearch: {
      type: Boolean,
      default: true,
    },
  },
  data() {
    return {
      toView: 'city-letter-Find', //锚链接 初始值
      scrollTop: 0, //scroll-view 滑动的距离
      cityindexs: [], // 城市索引
      activeCityIndex: '', // 当前所在的城市索引
      handleCity: [], // 处理后的城市数据
      serachCity: '', // 搜索的城市
      cityData: [],
    };
  },
  computed: {
    /**
     * @desc 城市列表排序
     * @return  Array
     */
    sortItems() {
      for (let index = 0; index < this.handleCity.length; index++) {
        if (this.handleCity[index].isCity) {
          let cityArr = this.handleCity[index].citys;
          cityArr = cityArr.sort(function (a, b) {
            var value1 = a.unicode;
            var value2 = b.unicode;
            return value1 - value2;
          });
        }
      }
      return this.handleCity;
    },
    /**
     * @desc 搜索后的城市列表
     * @return Array
     */
    searchDatas() {
      var searchData = [];
      for (let i = 0; i < this.cityData.length; i++) {
        if (this.cityData[i][this.formatName].indexOf(this.serachCity) !== -1) {
          searchData.push({
            oldData: this.cityData[i],
            name: this.cityData[i][this.formatName],
          });
        }
      }
      return searchData;
    },
  },
  created() {
    // 初始化城市数据
    this.cityData = this.obtainCitys;
    this.initializationCity();
    this.buildCityindexs();
  },
  watch: {
    obtainCitys(newData) {
      this.updateCitys(newData);
    },
  },
  methods: {
    /**
     * @desc 初始化
     */
    updateCitys(data) {
      if (data && data.length) {
        this.cityData = data;
        this.initializationCity();
        this.buildCityindexs();
      }
    },
    /**
     * @desc 监听输入框的值
     */
    keyInput(event) {
      this.serachCity = event.detail.value;
    },
    /**
     * @desc 初始化城市数据
     * @return undefind
     */
    initializationCity() {
      this.handleCity = [];
      const cityLetterArr = [
        'A',
        'B',
        'C',
        'D',
        'E',
        'F',
        'G',
        'H',
        'I',
        'J',
        'K',
        'L',
        'M',
        'N',
        'O',
        'P',
        'Q',
        'R',
        'S',
        'T',
        'U',
        'V',
        'W',
        'X',
        'Y',
        'Z',
        '#',
      ];
      for (let index = 0; index < cityLetterArr.length; index++) {
        this.handleCity.push({
          name: cityLetterArr[index],
          isCity: false, // 用于区分是否含有当前字母开头的城市
          citys: [], // 存放城市首字母含是此字母的数组
          forName:
            'city-letter-' +
            (cityLetterArr[index] == '#' ? '0' : cityLetterArr[index]), //label的绑定
        });
      }
    },
    /**
     * @desc 得到城市的首字母
     * @param str String
     */
    getLetter(str) {
      return citySelect.getFirstLetter(str[0]);
    },
    /**
     * @desc 构建城市索引
     * @return undefind
     */
    buildCityindexs() {
      this.cityindexs = [];
      for (let i = 0; i < this.cityData.length; i++) {
        // 获取首字母
        const cityLetter = this.getLetter(
          this.cityData[i][this.formatName],
        ).firstletter;
        // 获取当前城市首字母的unicode，用作后续排序
        const unicode = this.getLetter(
          this.cityData[i][this.formatName],
        ).unicode;

        const index = this.cityIndexPosition(cityLetter);
        if (this.cityindexs.indexOf(cityLetter) === -1) {
          this.handleCity[index].isCity = true;
          this.cityindexs.push(cityLetter);
        }

        this.handleCity[index].citys.push({
          cityName: this.cityData[i][this.formatName],
          unicode: unicode,
          oldData: this.cityData[i],
        });
      }
    },
    /**
     * @desc 滑动到城市索引所在的地方
     * @param id String 城市索引
     */
    cityindex(id) {
      this.toView = id;
      // //创建节点查询器
      // const query = uni.createSelectorQuery().in(this)
      // var that = this
      // that.scrollTop = 0
      // //滑动到指定位置(解决方法:重置到顶部，重新计算，影响:页面会闪一下)
      // setTimeout(() => {
      // 	query
      // 		.select('#city-letter-' + (id === '#' ? '0' : id))
      // 		.boundingClientRect(data => {
      // 			// console.log("得到布局位置信息" + JSON.stringify(data));
      // 			// console.log("节点离页面顶部的距离为" + data.top);
      // 			data ? (that.scrollTop = data.top) : void 0
      // 		})
      // 		.exec()
      // }, 0)
    },
    /**
     * @desc 获取城市首字母的unicode
     * @param letter String 城市索引
     */
    cityIndexPosition(letter) {
      if (!letter) {
        return '';
      }
      const ACode = 65;
      return letter === '#' ? 26 : letter.charCodeAt(0) - ACode;
    },
    /** @desc 城市列表点击事件
     *  @param Object
     */
    cityTrigger(item) {
      // 传值到父组件
      this.$emit('cityClick', item.oldData ? item.oldData : item);
    },
  },
};
</script>

<style lang="scss">
//宽度转换vw
@function vww($number) {
  @return ($number / 375) * 750 + rpx;
}

view {
  box-sizing: border-box;
}

.city-serach {
  width: 100%;
  color: #4a4a4a;
  padding: 0 vww(10);

  &-input {
    margin: vww(10) 0;
    height: vww(40);
    line-height: vww(40);
    font-size: vww(14);
    padding: 0 vww(5);
    border: 1px solid #4d8cfd;
    border-radius: 3px;
  }
}

.city-select-main {
  position: relative;
  // overflow: scroll;
  // -webkit-overflow-scrolling: touch;
  width: 100%;
  height: 100%;
  background: #f6f5fa;
  // overflow-y: auto;
}

.city-select {
  position: relative;
  width: 100vw;
  height: 100vh;
  background: #f6f5fa;

  // 热门城市
  .hot-title {
    padding-left: vww(23);
    width: 100vw;
    font-size: 14px;
    line-height: vww(40);
    color: #9b9b9b;
  }

  .hot-city {
    padding-left: vww(23);
    padding-right: vww(20);
    overflow: hidden;
    width: 100vw;

    .hot-item {
      float: left;
      padding: 0 vww(5);
      margin-right: vww(16);
      margin-bottom: vww(6);
      overflow: hidden;
      width: vww(100);
      height: vww(31);
      font-size: 14px;
      text-align: center;

      display: -webkit-box;
      -webkit-box-orient: vertical;
      -webkit-line-clamp: 1;

      line-height: vww(31);
      color: #4a4a4a;
      background: #fff;
      border: 1px solid #ebebf0;

      &:nth-child(3n) {
        margin-right: 0;
      }
    }

    .hot-hidden {
      display: none;
      margin-right: 0;
    }
  }

  .citys {
    .citys-row {
      padding-left: vww(18);
      width: 100%;
      font-size: 14px;
      background: #fff;

      .citys-item-letter {
        margin-left: vww(-18);
        padding-left: vww(18);
        margin-top: -1px;
        width: 100vw;
        line-height: vww(30);
        color: #9b9b9b;
        background: #f6f5fa;
        border-top: none;
      }

      .citys-item {
        width: 100%;
        line-height: vww(50);
        color: #4a4a4a;
        border-bottom: 1px solid #ebebf0;

        &:last-child {
          border: none;
        }
      }
    }
  }

  .city-indexs-view {
    position: absolute;
    right: 0;
    top: 0;
    z-index: 999;
    display: flex;
    width: vww(20);
    height: 100%;
    text-align: center;

    .city-indexs {
      width: vww(20);
      text-align: center;
      vertical-align: middle;
      align-self: center;

      .city-indexs-text {
        margin-bottom: vww(10);
        width: vww(20);
        font-size: 12px;
        color: #4d8cfd;

        &:last-child {
          margin-bottom: 0;
        }
      }
    }
  }
}
</style>
